1,721,125 research outputs found
Optimization of the SLED phase modulation parameters of the FERMI Linac
No full textFERMI is a single-pass linac-based FEL user-facility covering the wavelength range from 80 nm to 4 nm and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The first FEL line in operation (FEL-1) has been opened to users at the end of 2012, while the second FEL line (FEL-2) covering the shorter wavelength range down to 4 nm is in commissioning. The linac is composed of 16 S-band accelerating structures. Seven of them are backward structures equipped with SLED system. Following the preliminary tests on one plant, in order to increase the operational accelerating gradient, phase modulation of the SLED drive power has been implemented in all these structures. The shape of the phase modulation is applied via the LLRF system firmware and can be modified if needed. This paper discusses the optimization of the phase modulation parameters and provides a summary of the experimental results
Numerical analysis of magnetic field diffusion in ferromagnetic laminations by minimization of constitutive error
No full textIn this article, the diffusion of electromagnetic fields into a ferromagnetic lamination is numerically studied by means of an error-based numerical method. This technique has been developed so far only for the case of nonhysteretic constitutive relations. The generalization to the hysteretic case requires a modification of the technique in order to take into account the evolution of the “magnetization state” of the media. Numerical computations obtained by using this approach are reported and discusse
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Application of an exactly invertible hysteresis model to magnetic field computations
No full textWe consider an hysteresis model recently proposed, where the magnetic constitutive law M(H) is derived from considerations on domain wall motion. For this model we show that it is possible to build up the inverse constitutive law H(M), exactly. The inverse constitutive relation is applied to one-dimensional numerical computation of flux distributions and eddy currents in a magnetic slab
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